I figured out what was wrong with the xb-600 and what to fix. On the right handle which functions as the throttle, there are 2 parts to the brake. 1 is a nub that functions to stop the electrical motor and the other is a cantilever brake that stops the bike manually. What was wrong was that somewhere along the line the connection had either gotten loose or stopped completing the circuit. For this reason alone did the bike stop braking normally. I'm now considering two options buy a completely new right hand brake and switch or fix it myself. I can't put up pictures right now because I have no way of transferring them.
However, the best I can describe it as is a basically in parts:
Wires leading to pins -> pins soldered to wires -> pins attached to plastic casing ->plastic casing houses spring inside-> connects to plastic nub that sticks out of casing cover ( can be seen when brake is pulled back)
The function of that little plastic nub is to basically complete a circuit that stops the bike.
I might be able to send pics later, but the question I'm really curious for is the order in which the parts would go together:
There are three parts:
IIIIIII* <-----O-----> (nub with circular ring that serves as the switch for the circuit.)
*(spring -tapers up and becomes a bit more conical)
How to put the ring in such way that it only works when needed.